Nuclear Engineering Commons^™

Fsae Rear Differential Carrier, Nicholas Rivero, Peter Quach, Zack Jillani

Capstone Design Expo Posters

The Formula SAE design project enables engineering students to develop, analyze, build, and benchmark a Formula-style racecar. A differential was designed for VCU’s car to ensure that power is evenly distributed to the drive wheels under all possible handling conditions. A mounting system is required to secure the differential to the frame. Failure of this carrier could be catastrophic, therefore precise consideration of all possible forces and loading situations is required for design. A team was developed to examine how dynamic forces and fatigue contribute to component failure. Based on the results of this analysis a differential carrier can be …

Tapered Roller Bearing Accelerated Fatigue Life Test Rig Design, Hilton Bennett, Elizabeth Englert, Beck Grimm, Nathan Morris, Matthew Ofsonka, David Trinh

Capstone Design Expo Posters

Fatigue life testing of large tapered roller bearings for railroad applications is both expensive and time consuming. Accepted methods for testing bearings include full–size and scaled down testing. Currently, bearing test methods at Brenco take up to six months to complete, and scaled down testing requires additional resources for manufacturing prototypes and testing capabilities that are not economically ideal. The purpose of this project is the development of a tapered roller bearing test rig to test bearings to their fatigue life as quickly as possible. The rig design can accommodate bearing sizes in the range of one half (½) to …

Low-Cost Desalination Unit: Direct Contact Membrane Distillation, Meghan Herbert-Walters, Aubrey Martin, Lauren Scolese, Tina Trinh

Capstone Design Expo Posters

According to the United Nations Educational, Scientific, and Cultural Organization (UNESCO), 783 million people do not have access to a reliable clean water source. With this many people in the world without access to clean water, a solution to this problem is highly essential. The objective of this project is to create a low-cost compact desalination unit that can be used to turn contaminated water into pure drinking. For our design, a direct contact membrane distillation (DCMD) approach was used. The DCMD system allows only for the evaporated feed water to pass through the membrane and therefore causes an increase …

The Perfect Coffee Cup, Suzanne Bowers, Jessica Ingram, David Murphy, Gillian Stavlas

Capstone Design Expo Posters

To design a coffee cup that will maintain the coffee at the optimal drinking temperature for several hours using Phase Change Material, PCM. The importance of this project is designing a coffee cup that will retain its temperature for a prolonged period of time giving the consumer plenty of time to finish their coffee at the desired consumption temperature. We designed a double walled cup that would contain the PCM. Heat transfer calculations were done for different materials such as acrylic, glass, and stainless steel with various thicknesses for each material. These calculations were used to decide on the ideal …

Molten Metal Loop Driven By Electromagnetic Pump, Dominic Espiritu, Dor Granek, Jerald Moore, Scott Torres

Capstone Design Expo Posters

The first challenge of this proposed study was the gauges for the loop, which were not functioning properly and giving off inaccurate data due to a loop flow issue. Therefore a new loop design, including gauges, was created to gather accurate data for the electromagnetic pump. The electromagnetic pump used in this experiment differs from the standard electromagnetic motors by using rare earth magnets set into opposing steel plates that rotate simultaneously. Accurate data from the velocity and pressure gauges is necessary so the correlation between the EM pump’s speed and the flow velocity could be calculated. This technology could …

Fsae Rear Diffuser Team, Zarwan Waqar, Sohail Hossini, Saman Usodan

Capstone Design Expo Posters

To generate additional force that is applied to the rear of the FSAE race car The importance of the rear diffuser is to add a rear force to the vehicle. The rear force is generated from the airflow coming from underneath the vehicle. The way the airflow creates a force is through generating a pressure differential in which the air exiting the rear of the race car is now causing a downward force from the diffuser. The use of a diffuser is known to be of use at high speeds and if designed correctly creating the aerodynamics needed to keep …

Main Body Aerodynamics, Michael Al-Badini, Christopher Buettner, Wesley Russell, Steven Summerville, Marcus Wardlow

Capstone Design Expo Posters

Our senior design project entails designing, analyzing the front upper aerodynamic nose for the Formula SAE at VCU’s race team. Currently there are no provisions on the chassis to provide relief for parasitic loss of speed & efficiency due to drag. Since Formula SAE is focused on building a engineered, safe, and efficient vehicle our aerodynamic design will help with handling, downforce, and fuel economy all while reducing drag. Our Aerodynamic design will play a key role not only in how the Formula car is perceived aesthetically, but our calculations will be a large determining factor in the cars overall …

Lower Body Exoskeleton Powered By Epidermal Electronics Systems, Francis Azari, Forrest Baber, Saswat Mishra, Karan Patel, Juan Soto

Capstone Design Expo Posters

The purpose of our design revolves around the concept of enhancing the human body through the use of a lower body exoskeleton. The most applicable demographics for our design consists of paraplegics and non-paraplegics. The various uses we hope to include would allow the user to: walk again, lift heavier loads with the ability to move forward, back and be seated. Although lower body exoskeletons already exist on the market, they still have shortcomings that prevent widespread use among the general public. Our hope is to improve upon the design of existing exoskeletons with the integration of epidermal electronic systems …

Neutron Spectroscopy With Scintillation Detectors Using Wavelets, Jessica Hartman

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research was to study neutron spectroscopy using the EJ-299-33A plastic scintillator. This scintillator material provided a novel means of detection for fast neutrons, without the disadvantages of traditional liquid scintillation materials. EJ-299-33A provided a more durable option to these materials, making it less likely to be damaged during handling. Unlike liquid scintillators, this plastic scintillator was manufactured from a non-toxic material, making it safer to use, as well as easier to design detectors. The material was also manufactured with inherent pulse shape discrimination abilities, making it suitable for use in neutron detection.

The neutron spectral unfolding …

Understanding The Global Energy Crisis, Eugene D. Coyle, Richard A. Simmons

Purdue University Press Books

We are facing a global energy crisis caused by world population growth, an escalating increase in demand, and continued dependence on fossil-based fuels for generation. It is widely accepted that increases in greenhouse gas concentration levels, if not reversed, will result in major changes to world climate with consequential effects on our society and economy. This is just the kind of intractable problem that Purdue University’s Global Policy Research Institute seeks to address in the Purdue Studies in Public Policy series by promoting the engagement between policy makers and experts in fields such as engineering and technology.

Major steps forward …

Hybrid Tio2 Solar Cells Produced From Aerosolized Nanoparticles Of Water-Soluble Polythiophene Electron Donor Layer, Marshall L. Sweet, Joshua G. Clarke, Dmitry Pestov, Gary C. Tepper, James T. Mcleskey Jr.

Mechanical and Nuclear Engineering Publications

Hybrid solar cells (HSCs) with water soluble polythiophene sodium poly[2-(3-thienyl)-ethyloxy-4-butylsulfonate] (PTEBS) thin films produced using electrospray deposition (ESD) were fabricated, tested, and modeled and compared to devices produced using conventional spin coating. A single device structure of FTO/TiO2/PTEBS/Au was used to study the effects of ESD of the PTEBS layer on device performance. ESD was found to increase the short circuit current density (J_sc) by a factor of 2 while decreasing the open circuit voltage (V_oc) by half compared to spin coated PTEBS films. Comparable efficiencies of 0.009% were achieved from both device construction types. Current-voltage …

Computational Modeling And Experimental Study On Optical Microresonators Using Optimal Spherical Structure For Chemical Sensing, Hanzheng Wang, Lei Yuan, Jie Huang, Xinwei Lan, Cheol-Woon Kim, Lan Jiang, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

Chemical sensors based on optical microresonators have been demonstrated highly sensitive by monitoring the refractive index (RI) changes in the surrounding area near the resonator surface. In an optical resonator, the Whispering Gallery Modes (WGMs) with high quality (Q) factor supported by the spherical symmetric structure interacts with the contiguous background through evanescent field. Highly sensitive detection can be realized because of the long lifetime of the photons. The computational models of solid glass microspheres and hollow glass spheres with porous wall (PW-HGM) were established. These two types of microresonators were studied through simulations. The PWHGM resonator was proved as …

Self-Healing Of Ionomeric Polymers With Carbon Fibers From Medium-Velocity Impact And Resistive Heating, Vishnu Baba Sundaresan, Andrew Morgan, Matt Castellucci

Mechanical and Nuclear Engineering Publications

Self-healing materials science has seen significant advances in the last decade. Recent efforts have demonstrated healing in polymeric materials through chemical reaction, thermal treatment, and ultraviolet irradiation. The existing technology for healing polymeric materials through the aforementioned mechanisms produces an irreversible change in the material and makes it unsuitable for subsequent healing cycles. To overcome these disadvantages, we demonstrate a new composite self-healing material made from an ionomer (Surlyn) and carbon fiber that can sustain damage from medium-velocity impact and heal from the energy of the impact. Furthermore, the carbon fiber embedded in the polymer matrix results in resistive heating …

On Applications And Limitations Of One-Dimensional Capillarity Formulations For Media With Heterogeneous Wettability, T. M. Bucher, H. Vahedi Tafreshi

Mechanical and Nuclear Engineering Publications

Force-balance-based one-dimensional algebraic formulations that are often used in characterizing the capillarity of a multi-component system (e.g., predicting capillary height rise inporous media) are discussed. It is shown that such formulations fail to provide accurate predictions when the distribution of wetting (or non-wetting) surfaces is not homogeneous. A more general mathematical formulation is suggested and used to demonstrate that for media with heterogeneous wettability, hydrophilic (or hydrophobic) surfaces clustered in groups will have less contribution to the overall capillarity of the system.

Multiphase Hydrodynamics In Steady And Pulse Jet Mixing Systems, Ibraheem R. Muhammad

Dissertations

The goal of the present study is to evaluate the mixing performance of jet mixers in both liquid and solid-liquid mixing processes. Jet mixers have been studied for decades for its uses in liquid blending and solid-liquid mixing applications. In solid suspension processes, jet mixers can be just as useful if not more useful than conventional impeller mixers. However, there is a lack of phenomenological models that exist. The erosion and subsequent suspension of solids beds, as well as the suspension of a low concentration of solid particles must be better understood. The specific objectives were to develop analytical, experimental …

Evolutionary Optimization Of Electronic Circuitry Cooling Using Nanofluid, Manu Mital

Mechanical and Nuclear Engineering Publications

Liquid cooling electronics using microchannels integrated in the chips is an attractive alternative to bulky aluminum heat sinks. Cooling can be further enhanced using nanofluids. The goals of this study are to evaluate heat transfer in a nanofluid heat sink with developing laminar flow forced convection, taking into account the pumping power penalty. The proposed model uses semi-empirical correlations to calculate effective nanofluid thermophysical properties, which are then incorporated into heat transfer and friction factor correlations in literature for single-phase flows. The model predicts the thermal resistance and pumping power as a function of four design variables that include the …

Optimizing Fiber Cross-Sectional Shape For Improving Stability Of Air–Water Interface Over Superhydrophobic Fibrous Coatings, B. Emami, Hooman Vahedi Tafreshi

Mechanical and Nuclear Engineering Publications

In this letter, a mathematical force-balance formulation is developed that can be used to predict the critical pressure, the hydrostaticpressure above which the surface starts to depart from the non-wetting state, for superhydrophobicsurfaces comprised of highly aligned fibers (e.g., biased AC-electrospun coatings) with arbitrary cross-sectional shapes. We have also developed a methodology for optimizing the fiber cross-sections to maximize the critical pressure of the surface, using the Euler–Lagrange equation. A case study is presented to better demonstrate the application of our method.

Effect Of Fiber Orientation On Shape And Stability Of Air-Water Interface On Submerged Superhydrophobic Electrospun Thin Coatings, B. Emami, H. Vahedi Tafreshi, M. Gad-El-Hak, G. C. Tepper

Mechanical and Nuclear Engineering Publications

To better understand the role of fiber orientation on the stability of superhydrophobicelectrospun coatings under hydrostaticpressures, an integro-differential equation is developed from the balance of forces across the air–water interface between the fibers. This equation is solved numerically for a series of superhydrophobicelectrospun coatings comprised of random and orthogonal fiber orientations to obtain the exact 3D shape of the air–water interface as a function of hydrostaticpressure. More important, this information is used to predict the pressure at which the coatings start to transition from the Cassie state to the Wenzel state, i.e., the so-called critical transition pressure. Our results indicate …

Predicting Shape And Stability Of Air–Water Interface On Superhydrophobic Surfaces Comprised Of Pores With Arbitrary Shapes And Depths, B. Emami, Dr. Hooman Vahedi Tafreshi, M. Gad-El-Hak, Gary C. Tepper

Mechanical and Nuclear Engineering Publications

An integro-differential equation for the three dimensional shape of air–water interface on superhydrophobicsurfaces comprised of pores with arbitrary shapes and depths is developed and used to predict the static critical pressure under which such surfaces depart from the non-wetting state. Our equation balances the capillary forces with the pressure of the air entrapped in the pores and that of the water over the interface. Stability of shallow and deep circular, elliptical, and polygonal pores is compared with one another and a general conclusion is drawn for designing pore shapes for superhydrophobicsurfaces with maximum stability.

Quantification Of Stochastic Uncertainty Propagation For Monte Carlo Depletion Methods In Reactor Analysis, Quentin Thomas Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Monte Carlo method provides powerful geometric modeling capabilities for large problem domains in 3-D; therefore, the Monte Carlo method is becoming popular for 3-D fuel depletion analyses to compute quantities of interest in spent nuclear fuel including isotopic compositions. The Monte Carlo approach has not been fully embraced due to unresolved issues concerning the effect of Monte Carlo uncertainties on the predicted results.

Use of the Monte Carlo method to solve the neutron transport equation introduces stochastic uncertainty in the computed fluxes. These fluxes are used to collapse cross sections, estimate power distributions, and deplete the fuel within depletion …

Simulation And Validation Of Two-Component Flow In A Void Recirculation System, Oscar Eduardo Daza

Master's Theses

Nuclear power plants rely on the Emergency Core Cooling System (ECCS) to cool down the reactor core in case of an accident. Occasionally, air is entrained into the suction piping of ECCS causing voids that decrease pumping efficiency, and consequently damage the pumps. In an attempt to minimize the amount of voids entering the suction side of the pump in ECCS, a Void Recirculation System (VRS) experiment was conducted for a proof of concept purpose. While many studies have been oriented in studying two-component flow behavior in ECCS, none of them propose a solution to minimize air entrainment. As a …

Computational Study Of Passive Neutron Albedo Reactivity (Pnar) Measurement With Fission Chambers, Sandra De La Cruz

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Passive Neutron Albedo Reactivity technique (PNAR) was used to assay used nuclear fuel as a potential method for the measurement of fissionable material in fuel assemblies. A Monte Carlo transport code (MCNPX 2.6) was used to develop simulation models to evaluate the PNAR technique. The MCNPX simulated models consisted of two 17x17 Pressurized Water Reactor (PWR) used fuel assemblies; one with an initial 3 wt% uranium-235*, cooled for 20 years and second with an initial 4 wt% uranium-235*, cooled for 5 years. Each used fuel assembly was simulated at four different burn up rates of 15, 30, 45, and …

Predicting Shape And Stability Of Air–Water Interface On Superhydrophobic Surfaces With Randomly Distributed, Dissimilar Posts, B. Emami, Hooman Vahedi Tafreshi, M. Gad-El-Hak, Gary C. Tepper

Mechanical and Nuclear Engineering Publications

A mathematical framework developed to calculate the shape of the air–water interface and predict the stability of a microfabricated superhydrophobicsurface with randomly distributed posts of dissimilar diameters and heights is presented. Using the Young–Laplace equation, a second-order partial differential equation is derived and solved numerically to obtain the shape of the interface, and to predict the critical hydrostatic pressure at which the superhydrophobicity vanishes in a submersed surface. Two examples are given for demonstration of the method’s capabilities and accuracy.

Application Of The Tdma Technique Toward The Size And Charge Distribution Measurement Of Graphite, Gold, Palladium, And Silver Aerosols, Matthew Paul Simones

All Graduate Theses, Dissertations, and Other Capstone Projects

The knowledge of charge distributions among aerosol particles has been an important topic for many years because of the strong electrostatic interactions which can greatly influence aerosol transport and evolution. Theoretical models have been developed although experimental verification has been limited because of the difficulty in measuring charged aerosols. Recently a method utilizing a tandem differential mobility analyzer (TDMA) has been shown to be applicable toward measuring both the size and charge distributions of nanosized combustion aerosols. The goal of this work is on further exploration of this method toward the measurement of non-combustion aerosols and in particular those associated …

Triso Fuel Compact Thermal Conductivity Measurement Instrument Development, Colby Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermal conductivity is an important thermophysical property needed for effectively predicting fuel performance. As part of the Next Generation Nuclear Plant (NGNP) program, the thermal conductivity of tri-isotropic (TRISO) fuel needs to be measured over a temperature range characteristic of its usage. The composite nature of TRISO fuel requires that measurement be performed over the entire length of the compact in a non-destructive manner. No existing measurement system is capable of performing such a measurement.

A measurement system has been designed based on the steady-state, guarded-comparative-longitudinal heat flow technique. The system as currently designed is capable of measuring cylindrical samples …

Impact Investigation Of Reactor Fuel Operating Parameters On Reactivity For Use In Burnup Credit Applications, Tanya N. Sloma

UNLV Theses, Dissertations, Professional Papers, and Capstones

When representing the behavior of commercial spent nuclear fuel (SNF), credit is sought for the reduced reactivity associated with the net depletion of fissile isotopes and the creation of neutron-absorbing isotopes, a process that begins when a commercial nuclear reactor is first operated at power. Burnup credit accounts for the reduced reactivity potential of a fuel assembly and varies with the fuel burnup, cooling time, and the initial enrichment of fissile material in the fuel. With regard to long-term SNF disposal and transportation, tremendous benefits, such as increased capacity, flexibility of design and system operations, and reduced overall costs, provide …

In-Pile Thermal Conductivity Measurement Methods For Nuclear Fuels, Brandon S. Fox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measuring nuclear fuel thermal conductivity in-pile can provide much needed data for understanding fuel performance during irradiation and yield thermophysical property data needed for simulation codes and fuel databases. The objective of this research is to develop and compare two in-pile thermal conductivity methods in a laboratory setting using surrogate fuel materials.

A steady-state radial heat flow method was investigated to understand its viability as an in-pile steady-state thermal conductivity technique. By using Joule heating to simulate volumetric heat generation within a surrogate fuel rod, thermal conductivity was measured with two thermocouples at different radial positions within the rod. Examinations …

Bennett Clocking Of Nanomagnetic Logic Using Multiferroic Single-Domain Nanomagnets, Jayasimha Atulasimha, Supriyo Bandyopadhyay

Mechanical and Nuclear Engineering Publications

The authors show that it is possible to rotate the magnetization of a multiferroic (strain-coupled two-layer magnetostrictive-piezoelectric)nanomagnet by a large angle with a small electrostatic potential. This can implement Bennett clocking [Int. J. Theor. Phys.21, 905 (1982)] in nanomagnetic logic arrays resulting in unidirectional propagation of logic bits from one stage to another. This method is potentially more energy efficient than using spin-transfer torque for magnetization rotation. For realistic parameters, it is shown that a potential of ∼0.2 V applied to a multiferroicnanomagnet can rotate magnetization by nearly 90° to implement Bennett clocking.

The Very Basics Of Sustainability - An Alternative Viewpoint (Slides With Audio) (Large File! To Speed Up Download, Right-Click On "Download" Link To Save To Own Pc.), Jim Mcgovern

Other resources

This presentation sets out the very basics of ‘sustainability’, although a definition of sustainability is not attempted. Some of the very basics are the context in which the Earth and humankind exist in space and time, the Earth’s climate, the Earth’s population and humankind’s options and choices. The author advocates keeping an open mind on all available options, including the use of oil, gas, coal, tar sands, carbon capture and sequestration, nuclear power etc., as well as the technologies that are more widely considered ‘green’. The author also argues that, in addressing the challenges that humankind faces, globally concerted effort …

Demonstration Of A Completely Described Swirling Jet Experiment Used For Numerical Validation, Brandon M. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis demonstrates the standard for the design of an experimental model to be used for numerical validation purposes. It is proposed that numerical models may be assessed more accurately and directly by validation with a completely described experimental model, consisting of accurate descriptions of the operating conditions, fluid properties, and experimental uncertainties. This idea is demonstrated using an experimental model of a swirling jet at three Reynolds numbers (Re = 550, 2560, and 3650), with vortex breakdown existing in the higher two Reynolds number cases. Measurements of the swirling jet were obtained at two locations upstream of the jet …